Baltimore, Maryland — It's a hot Sunday morning in Oliver, a blighted Baltimore neighborhood, and Dave Landymore is filthy. Two decades of basement dust cling to his jeans as the former Marine platoon sergeant hauls boxes of old baby things down the sidewalk to a giant dumpster.

They come from a house on Holbrook Street, known here as "Hellbrook." Once a feared hub of the city's drug trade, it has been Carolyn Lawson's home as she raised three children and cared for seven grandchildren. Now, though she struggles to walk, she is desperate to stay in her house. But it needs urgent repairs that the city won't make under a weatherization program until her basement is emptied of decades' worth of storage.

Mr. Landymore and a dozen other volunteers working at Mrs. Lawson's this morning are part of a veteran-led effort called Operation Oliver. Since October 2011, the group has been cleaning up trash and helping residents across the largely poor, African-American neighborhood. Along blocks dotted with boarded-up homes, where drug dealers run the corners at night, veterans are applying lessons they learned in Iraq and Afghanistan in an effort to restore the community's sense of pride – and their own sense of purpose.

As the United States ends long occupations in Afghanistan and Iraq, some 200,000 service members each year are making the transition back to civilian life. Coming home from war has never been easy, for soldiers or society, and today's veterans face particular challenges, from the unprecedented number who suffered brain injuries in combat to the unforgiving economy that is waiting for them. But they also have particular strengths: They are an altruistic generation that volunteered to serve, many of whose members worked overseas rebuilding broken communities. Now, they're bringing that spirit home, and many are searching for ways to express it in their civilian lives.

For some in Baltimore, Operation Oliver is now an outlet for this sense of mission. The project's work has yielded real successes – as well as conflict in a community that is in some ways as foreign to them as those they patrolled overseas. But with time, both sides have learned and grown, and more veterans, including Landymore, have moved to the area and devoted themselves to the project. What they've forged here could become a model for other complex revitalization efforts across the country.

"Unfortunately, the tendency is to thank a veteran for their service, pat them on the butt, and say: 'Go on, now,' " says Landymore. "But we all joined for the same reason; and just because you have your discharge papers doesn't mean the reason goes away, the sense of duty.... So until it becomes a matter of policy to engage veterans in this way, we're just going to do it anyways."

* * *

Operation Oliver began last summer, when an acquaintance introduced two energetic young do-gooders: Earl Johnson, a former Army Ranger who had recently moved to Oliver, and Rich Blake, a former Marine Corps sergeant who was missing the purpose and camaraderie he'd found overseas.

Mr. Blake was discharged in 2003, after more than four years as a combat marine. Civilian life felt like a letdown, he says, and he searched for a way "to feel useful again."

Experts say that's a common complaint from returning veterans. Since the 9/11 terrorist attacks, 2.7 million American service members have become civilians again. It's a huge adjustment, not just for those with traumatic injuries or memories, but for all who face the question: How do I build a meaningful life back home?

"People feel like they need to matter to something bigger than themselves, bigger than a task and marching orders," says Meredith Kleykamp, a researcher at the University of Maryland in College Park who studies veteran unemployment. "Veterans had that [in the military], and they didn't have to go out and find it – it was given to them."

As they return to civilian life, she says, it falls to them to choose their own missions – often for the first time.

Jobs are hard for veterans to find these days. In April, the Bureau of Labor Statistics reports, 9.2 percent of veterans who had served since 9/11 were unemployed, compared with 7.6 percent of nonveterans. A recent 4,000-member survey by the nonprofit Iraq and Afghanistan Veterans of America found even higher rates, including 35.7 percent unemployment among 20-to-24-year-old veterans of the two wars.

Many factors contribute, from poor transition training, to the difficulty of translating military experiences and skills into civilian language and jobs, to some employers' nervousness about veterans' stability. New initiatives like the "VOW to Hire Heroes Act" President Obama signed in November, and his proposed Veterans Job Corps, may help.

But beyond the challenge of finding a job is the challenge of finding civilian work, paid or not, that is as compelling as members' service overseas. Nationwide, a few nonprofits – including Team Rubicon, an international disaster-response corps, and The Mission Continues, a volunteer-support organization – are trying to harness veterans' continuing desire to do mission-driven work. But for now, they're the exception.

As Blake was looking for a way to make an impact back home, he visited his local Veterans of Foreign Wars post. There, he met other young vets who were similarly adrift, and together they founded a nonprofit called The 6th Branch – envisioning a community service organization to join the other five branches of the military.

The group tackled various volunteer projects, trying to settle on a cause, but nothing stuck. Eventually, Blake reenlisted. The 6th Branch seemed ready to disband.

* * *

Meantime, newlyweds Earl and Zenitha Johnson had just bought a home on a quiet, leafy Baltimore street called Eden. They didn't know much about the area, but what they had heard wasn't great: Parts of the gritty HBO drama "The Wire" had been filmed there because of all the vacant buildings and ambient drug dealing.

A century ago, Oliver was known for its stately brick row houses with carved cornices and white marble stoops. Today, a third of these stand vacant, and more are falling to ruin around their inhabitants. Liquor stores outnumber all other kinds of businesses, and the number of residents who remember Oliver as a proud, vibrant community grows smaller every year.

Lawrence Pully, who moved there as a kid in the 1940s, is one of them. "I remember scrubbing those steps," he says. He and his friends got paid for it, sometimes in pennies and nickels, sometimes in empty soda bottles they could exchange at the store.

In those days, Oliver was a working-class African-American community with a thriving business district. Then, in April 1968, riots consumed the city after the death of Martin Luther King Jr. The arson and looting got so bad that National Guard troops marched up Oliver Street to restore calm.

The neighborhood never recovered. Crack cocaine moved in, then heroin. Residents who could, fled, leaving whole blocks abandoned. The "Hamsterdam" episode of "The Wire," in which police try to reduce crime by essentially legalizing the drug trade along certain streets of vacant homes, was shot there..

In 2002, an Oliver family with five children was burned to death in their home after the mother confronted local dealers. Money poured into the area, and a playground and children's center now memorialize the family. More recently, an alliance between a local ministers' group called BUILD and The Reinvestment Fund, a Baltimore nonprofit group that invests in distressed neighborhoods, has been working to build and rehab subsidized housing in the southeast corner of Oliver, near Johns Hopkins Medical Center and a planned biotech park.

Mr. Johnson, who grew up in a Baltimore suburb, had never really spent time in the city before moving there. "So I get to Baltimore as an adult, and I'm like: 'Who dropped the ball here?' "

He started beautifying the couple's little piece of Eden, planting trees and flowers and introducing himself to neighbors. He also met Dave Borinsky, who had invested in rehabbing his house. Mr. Borinsky was starting Come Home Baltimore, a for-profit development firm in the neighborhood, which was paired with a nonprofit foundation of the same name. The mission of the two organizations is to rehab vacant homes for sale, while helping current residents tap into assistance programs to fix up their own.

He and Johnson hit it off, and Borinsky hired Johnson to lead the foundation. But Johnson's overtures to local leaders, who were wary of outside developers, met with frustration, and he was looking for a new approach.

* * *

When Johnson met Blake, the 6th Branch leader was organizing a service day through another nonprofit, the Pat Tillman Foundation. The impulsive pair clicked immediately and held the cleanup in Oliver. Standing on the back of a pickup truck at the end of a successful day, they committed themselves and their organizations to turning the neighborhood around.

Resident Donald Morton saw the project unfolding through the back window of the Oliver Street home he has shared with his mother for half a century. He went out to help, and became a convert.

"I never seen that many women come down and do that kind of work," he says of the volunteers. "That kind of pumped me up. They were swinging axes and everything."

Sitting on his stoop on a recent evening, Mr. Morton remembers, as a kid, watching Army tanks roll up the street to quell the riots. He also recalls the dark decades that followed, when the place was crawling with drug dealers.

Things are much quieter today, he says: "Now, the most I have to deal with is my mom."

Since the first cleanup Morton helped with last July, nearly 2,000 volunteers – mostly college students from the Baltimore area and farther afield – have come to help in Oliver. They and veteran leaders have planted more than 100 trees and shrubs, pulled over 65 tons of trash out of lots and alleys, and helped elderly residents empty their homes of more detritus.

Smaller groups of mostly combat veterans also conduct (unarmed) evening patrols through the neighborhood, help police identify drug targets, attend community meetings, report dumpsites and gas leaks to the city, and work with a local nonprofit called the Veteran Artist Program, whose members have been painting murals and developing plans for a playground and community garden in Oliver.

Johnson is out on the streets so much, he has become like an unofficial mayor: Neighbors joke that his wife, Zenitha, is Oliver's first lady. More than once, their marriage has nearly been a casualty of his devotion to the neighborhood.

Though Blake and Johnson often act as spokesmen for Operation Oliver, officially the project has no top-down leadership, no fixed location, and no paid staff. The group survives on a shoestring, thanks to grants, private donations, and community fundraisers.

That appealed to Landymore. When he left active duty, besides taking college classes, he volunteered at the Chesapeake Bay Foundation, at a homeless shelter, and with a high school mentoring project. Nothing came close to the feeling he'd had in Anbar Province in Iraq. Then an acquaintance mentioned Operation Oliver. The idea of using his military training to make an impact at home spoke to him.

"Although I'm an undergraduate student at UMBC" – The University of Maryland, Baltimore County – "I'm also a platoon sergeant in the Marine Corps, in charge of 45 marines and 12 tactical vehicles…. You've got all these skills," he says. "With both wars coming to a close, it occurred to me there's going to be a lot of former service members back in civilian life, and we better find out what to do with them. Otherwise, we're going to wind up with another generation of Vietnam veterans: underappreciated, underutilized."

He contacted Blake, who invited him to the group's next project, hauling trash and brush out of a vacant lot.

"Right when I showed up, I asked Rich: 'What are my orders?' " Landymore says. "He just said: 'Make this place better.' "

Landymore and his pear-shaped tea mug became a constant, calming presence among the big personalities of Operation Oliver. Within a few months, he was renting a home on Bond Street. In April, when Blake left Baltimore to return to active duty, Landymore took over as executive director of The 6th Branch.

"It's easy to go serve soup one time a week and go home and feel good about yourself," he says. "But if you weren't there [serving], somebody else would. We're here every day. If we weren't here, my street would still be a completely open-air drug market. But it's not."

* * *

This Sunday morning, as grubby volunteers tromp up Lawson's front steps, everyone else outdoors seems to be headed to church. On neighboring blocks, old women in fanciful hats pick their way down crumbling sidewalks. In Oliver, the saying goes, there's a church on every corner. Though the churches are major power brokers in the neighborhood, members are mostly former residents who revisit the area on Sundays and have been praying for decades that it would turn around.

Members of Operation Oliver didn't come to pray. Initially, they saw the churches as part of what was holding the neighborhood back, by being too passive, and said so.

Marshall Prentice, who has led Oliver's Zion Baptist Church for a quarter century, disagrees. Over the years, his 1,100-member congregation has run a food pantry; paid neighbors' overdue rent and electric bills; provided havens for teens, people living with HIV, and victims of domestic abuse; participated in community health fairs and neighborhood prayer walks; cultivated strong relationships with local police; and lobbied to improve the lives of residents across the city.

"The most stable organism in the community is the church," says Pastor Prentice. "We'll be here when everyone else is closed down."

At first, Operation Oliver circumvented such networks and relationships. The veterans took immediate action, without holding community meetings, developing site plans, or seeking consensus. They saw this as a strength.

"That's what I hate about Baltimore – well, I guess anywhere. They'll create a task force to talk about trash," says Blake. "And the question is: When is anyone going to actually pick up any trash?"

The volunteers did – quickly, and with much media fanfare. This rubbed local leaders the wrong way. Mr. Pully saw their approach as arrogant. Now vice president of the Oliver Community Association, Pully says Operation Oliver leaders hadn't shown enough respect for neighborhood elders and the struggle they've been engaged in for decades.

Melvin Russell, commander of Baltimore's Eastern District police, puts it more bluntly. He says many community leaders thought the veterans came off as "jerks."

Volunteers see a number of possible sources for this frustration. "I think the reason there's been some pushback is that the rapidness with which we changed so much exposed what they hadn't been doing all these years," says Blake. "If we can come in for five months and remove 70 tons of trash and plant 100 trees, what were you doing for the last 20 years besides having meetings and singing on street corners?"

It's not unusual for the energy that veterans bring to postmilitary work to cause resentment. "Co-workers feel like: 'Hey, man, you're making us look bad,' " says T.L. McCreary, a retired Navy rear admiral and president of Military.com, an online resource for service members.

But Johnson thinks the problem wasn't just Operation Oliver's speed – it was their lack of diplomacy.

"We've stepped on a lot of toes, but we're trying to do better. That's not the way to do business," he says. "But I also think we had to show them first that we meant business."

Over time, the volunteers have come to see Oliver's churches as potential allies, and drug violence and medieval living conditions as their larger, mutual enemies.

In March, a group of Buffalo State University students helped the veterans clean a massive dumpster's worth of trash from the house of longtime Oliver resident Dave Hollins, an elderly man who lives with his granddaughter, April Cherry, on Lanvale Street. The two had been confined to the top floor of the house by old furniture and clutter, rodent infestation, and rotting floorboards on the first floor. Their kitchen is unusable. A hole in the wall lets in rats and the elements.

Volunteers spent a day clearing debris and animal carcasses out of the living space, though the city still considers the house too badly damaged to attempt repairs. Operation Oliver is trying to scrape together funding to tackle the most urgent needs.

On their walks around the neighborhood, Johnson and Landymore check in on the family. On a recent evening, Ms. Cherry marveled at how much the cleanup had changed their lives. "Sometimes I just play my music upstairs and come downstairs and dance," she says. "[There's] all this space."

As their focus has shifted somewhat, from park and alley cleanups to individual residents and their struggles, Operation Oliver leaders have softened their tone and cultivated closer relationships with Zion Baptist, the Eastern District police, and others.

"Some of the living conditions we've seen here have made us cry," says Johnson. "We've got people living like [they were in] Bosnia here."

He knows one elderly woman with no heat who boils water in winter so the steam will warm her. Another bails sewage from her basement into her yard with a bucket. "We won't have the impact we should have until we get into these houses," he says.

* * *

That's what volunteers are doing at Lawson's this morning: getting her home ready for weatherization so she can live in it safely. When they arrived, she struggled out to her stoop to say a blessing over them. Now, she sits in the living room with her young grandson, overseeing the parade of boxes emerging from the basement. "I'm looking at memories coming up the steps," she says.

Despite the hard years she spent in Oliver, when dealers ruled the park 20 yards from her door and taxi drivers bringing her home demanded payment upfront so they could drop her off and speed away, this is the place Lawson wants to live the rest of her life. She nursed her mother, mother-in-law, and husband through their final days in this house, and she wants to go the way they did – at home.

"I appreciate everything [the volunteers] have done to help me out," she says, " 'cause I know I couldn't have done it by myself."

Lawson was skeptical of the group at first; she had been on waiting lists for city assistance for a year and despaired that anyone was serious about getting things done. But the veterans charmed her.

"I talk to them like I talk to my sons," she says. "All of them are very friendly and helpful, and I can pick up their sense – you know, you can pick up a sense that a person is truly from the heart."

So Operation Oliver's effort to win over hearts and minds continues. "We're a foreign element, and in that way it's the same as it would be in Iraq or Afghanistan," says volunteer Jeremy Johnson, who is contemplating a move to the neighborhood. The important difference, he says, is that "here we have the ability to understand and adapt and bridge the gap. The people soldiering there [in Afghanistan or Iraq] were never going to stay. Here we can."

As members of Operation Oliver have become more diplomatic – and as their successes and the press they've generated have gotten the attention of the mayor, the police commissioner, and other powerful players across the city – both Oliver residents and leaders are coming to embrace a group that's eager to return the favor.

"I have nothing but praises for them now," says Mr. Russell, the police commander. At a recent meeting, he says, "it was like they are a different creature, and they want to play in the sandbox with everybody else."

Now, other organizations across the country are reading lessons into the group's experience: about volunteerism, about veteran unemployment, about reframing the national dialogue over how service members can contribute.

"It does show what our veterans are capable of outside the workplace – and even inside," says Jason Hansman of the Iraq and Afghanistan Members of America. "For every veteran doing Operation Oliver, there's probably 100 just like them who are unemployed."

Operation Oliver volunteers hope the initiative will be duplicated in other "veteran-sponsored communities" across the nation.

"People have grown afraid of the veteran because they can't separate the man with the machine gun from the man with the mission," says Landymore, nursing his tea. "But look what I'm doing now. It's not something special. It's what people who live in the community should be doing anyway.

"Maybe being a veteran makes me a little more of a leader to be able to accomplish it," he says. "But the message I want people to get is: 'This is a mission for you, not just a mission for us.' "